Electric clock fire alarm



y 8, 9 A. H. LAMB ELECTRIC CLOCK FIRE ALARM 2 Sheets-Sheet 1 Filed Sept.8, 1947 y 1951 A. H. LAMB 2,552,331

ELECTRIC CLOCK FIRE ALARM Filed Sept. 8, 1947 2 Sheets-Sheet 2 INVE OR.

WA BY Patented May 8, 1951 UNITED STATES PATENT OFFICE 2,552,331ELECTRIC CLOCK FIRE ALARM Anthony H. Lamb, Hillside, N. J. ApplicationSeptember 8, 1947, Serial No. 772,634

2 Claims. 1

This invention relates to fire alarm devices and more particularly tonovel combinations of devices that include an audible sound producingmember serving a primary function and provided with temperatureresponsive control means adapted to actuate the sound producing memberwhen the temperature of the surrounding air reaches a predeterminedvalue.

The appalling number of fatalities due to fire, especially in the homeand hotels, is a matter of public record. As a result of our technicaladvances we have moved into our homes and buildings tremendous forces ofpotential destruction in the form of electricity, gas, heating devices,radio antennae, chemicals, cleaning fluids, etc. In view of these, andmany other potential sources of fire, it is significant that a moregeneral use is not made of safety devices.

With respect to loss of life, it is known the critical period of a fireis the first few minutes and the greatest number of fatalities occur asa result of fires starting in the night. In the majority of the casesvictims find themselves trapped by fire because they were not aware ofthe danger until too late.

During the first few minutes of a fire there is a rapid generation ofheat, smoke, and poisonous gases. Unfortunately, the poisonous gasespermeate to other rooms in the building many minutes before a sharp risein temperature and the inhalation of these gases does not immediatelyawaken a sleeping person with the result that upon finaly awakening theperson is in a mental stupor and incapable of correct and decisiveaction.

It being a matter of record that the number of fire fatalities isdirectly related to the time elapsed between the actual start of thefire and a consciousness of the fires existence, the almost completeabsence of fire alarm devices in homes and hotels is a matter worthy ofinvestigation.

I am aware of the various, orthodox fire alarm devices and systemsavailable at present. These have not found general and wide use indwellings for various reasons such as the following:

1. The high cost of the device per'se.

2. High installation costs.

3. Unsightliness and damage to walls or woodwork caused by installation.

4. Intricate nature of device placing it beyond the confidence of theaverage user.

5. Complexity requiring a trained installer.

6. High maintenance costs.

At present there exist a wide variety of devices of unquestionedacceptance for use in the home 2 and which devices serve a primarypurpose of producing an audible signal or sound at selected periods.Examples of such devices are radio sets, door signals, electrical and/ormechanical clocks, etc. In its broad aspect my invention contemplatesthe provision of devices of this type and including auxiliary,temperature actuated means adapted to cause operation of the signal orsound producing member when the temperature of the surrounding airreaches a predetermined value. The temperature actuated means does notin any way interfere with the normal operation of the device.

A broad object of this invention is the provision of a sound producingmember serving a normal, primary purpose in combination with temperatureactuated control means whereby the sound producing member serves theadditional and complementary purpose of sounding an alarm when thetemperature of the surrounding air reaches a predetermined value.

With respect to a radio receiving set the invention contemplates theprovision of a temperature actuated switch associated with the volumecontrol circuit of the radio. Closure of the switch causes the receiverto be turned on to full or unusually high volume thus blaring forth anunmistakable warning.

It is a specific object of this invention to provide a radio receivingset in combination with a temperature actuated switch whereby thereceiver is turned on to high volume output when the temperature of thesurrounding air reaches a predetermined value.

With respect to door signals the invention contemplates the provision ofa temperature actuated switch establishing closure of the electricalcircuit in parallel with the door button. The temperature actuatedswitch is normally open and may be placed. in the chime housing or inany other desired location being connected to the signal system by twowires. When the temperature of the air surrounding the temperatureactuated switch reaches a predetermined value, the switch closes theelectrical circuit to the signal. A plurality of temperature actuatedswitches may be employed each located in an area to be protected.

In the case of the conventional single stroke door chime additional timedelay means are provided to cause periodic or recycling actuation of thesignal once the temperature actuated switch is caused to close.

It is, therefore, an object of this invention to provide temperatureactuated control means in combination with door signals whereby the doorsignal serves the additional and complementary purpose of sounding analarm when the temperature of the surrounding air reaches apredetermined value.

With respect to clocks the invention contemplates the provision of aconventional alarm clock provided with auxiliary temperature actuatedmeans adapted to sound the alarm upon a predetermined rise in thetemperature of the air surrounding the clock. The addition of thetemperature actuated means does not interfere with the normal,presettable alarm mechanism but once the temperature actuated means isset in operation the alarm continues to ring until reset by hand tocondition the device for a subsequent cycle of operation.

An object of this invention is the provision of an alarm clock providedwith auxiliary means adapted to sound an alarm when the temperature ofthe air reaches a predetermined value.

The above enumerated and other objects and advantages will be apparentfrom the following description when taken with the accompanying drawingsillustrating various embodiments of the invention. The drawings are forpurposes of illustration and are not to be construed as defining thescope or limits of the invention, reference being had for this purposeto the appended claims. i

In the drawings wherein like characters denote like parts in the severalviews:

Figure 1 is a central cross-sectional view showing a simple embodimentof a temperature actuated switch of the type contemplated by thisinvention;

Figure 2 is a diagram of the volume control circuit of a conventionalradio receiving set;

Figure 3 is a circuit diagram showing a functional adaptation of atemperature actuated switch designed to operate the volume control ofthe type shown in Figure 2;

Figure 4 is a circuit diagram illustrating the combination of a singlestroke door chime and a' temperature actuated switch of the recycling ypFigure 5 is a front view, in partial cross-section.

illustrating the adaptation of a temperature actuated deviceto aconventional electrical alarm clock.

be connected into an electrical circuit by solder ing wires 21 to theend thereof.

In the assembled unit, the blades 26, 2i normally are biased toward eachother to establish good mechanical and electrical contact between thecontact buttons 2B, 2!. However, the contact buttons are set in opencircuit position by interposing a pellet 28 between the blades 20, 2|substantially as shown. The pellet 28 comprises a material that is solidat normal room temperature but which melts at a specific, elevatedtemperature dependent upon the particular material employed. Various waxcompositions and metal alloys are suitable for this purpose.

For purposes of this description let it be as-.-

4 suined the pellet 28 comprises a compound having a melting point of110 F. At temperatures below this value the pellet 23 is a solid andretains the contacts 2| in spaced-apart relationship. When a fire breaksout in the vicinity of the pellet the surrounding air temperaturequickly exceeds 110 F. whereupon the pellet melts permitting closurebetween contacts Zil', 2i to establish an electrical circuit. It isapparent this construction provides a temperature actuated switchadapted to actuate various alarm or signal devices as will be describedin more detail hereinbelow. Once the pellet 28 has melted the contacts26', 2| remain closed until a new pellet is inserted between the switchblades. This is desirable to assure proper attention being given to thedevice itself and to conditions causing actuation thereof.

While I have thus far described a simple construction of the temperatureactuated switch it is apparent the device is subject to a wide range ofdesigns to meet specific requirements.

Referring now to Figure 2 there is shown a conventional volume controlcircuit of a radio receiving set comprising a potentiometer or volumecontrol 29 connected across the audio input stage. The strength of thesignal applied to the voice coil 36 of the loud speaker 34 is controlledby the voltage potential applied to the grid 32 01 the electron tube 33.Full volume out of the loud speaker is obtained by setting the slidecontact 34 to the upper end of the potentiometer 29.

Figure 3 illustrates the application of my temperature actuated switchto the volume control circuit of Figure 2 to convert the receiver to afire alarm. In this instance the switch comprises a series of metalblades, 35, '36, Bl, 38 and 39 provided with contact buttons 35a, 36aand 35b, Sia, 38a, and 39a respectively. Figure 3 is drawn to illustratefunctional operation rather than mechanical details as multi-bladeswitch arrangements of this type are well known in the art. Thetemperature sensitive pellet 28 is shown interposed between the longblade 36 and a fixed surface ti). Under this condition the contacts 35aand 36a are closed and all other contacts are open.

The switch blades 35 and 36 are interposed into the circuit of thevolume control by wires ll and 42 as shown. Inasmuch as the contacts 35aand 36a are normally closed, the slide contact 34 may be used in normalmanner to control the volume of the receiver. However, when thetemperature of the surrounding air reaches a predetermined value, aswhen a fire occurs in the room in which the radio receiver is located,the pellet 28 melts permitting blade 36 to move downward causing openingof the contacts 35a and 36a and closing of the contacts 36b and 31a.Under this condition the position of the slider 34 is immaterial as thefull voltage is applied to the grid 32 through wire 43, blade 31,contact 3111, contact 3%, blade 36 and wire 42. As thus far describedthe set is immediately conditioned for full volume output from the loudspeaker 3!. Therefore, it is apparent that if the radio set is inoperation at any volume level, the full volume blast from the speakerwill serve as a fire alarm.

Provision is also made to sound an alarm in this manner even though theradio set is turned off at the time of the fire. Electrical power issupplied to the radio from the power line by connecting the set to anelectrical outlet by means of a plug 44 and duplex cord 45. Power to thepower transformer 46 is controlled by an onoff switch 41, the radiobeing turned off when switch 41 is open. Connected in parallel with theswitch 41 are blades 38 and 39 of the temperature actuated switch bymeans of wires 48 and 49. As shown in Figure 3 the contacts 38a and 39aare normally open when the solid pellet 28 is in position. Therefore,control of the radio is within the discretion of the user. When thepellet 28 melts contacts 38a and 39a close thereby turning the radio on.Simultaneous closure of contacts 361) and 31a cause full voltage to beapplied to the grid of the tube. Thus, the loud speaker is caused tooperate at maximum volume. The nature of the sounds emitted by the loudspeaker are immaterial. Usually a radio set remains tuned to a givenbroadcasting station after it is turned off in which:.case theparticular program at excessive volume will serve as a fire alarm. Eventhough the set is not tuned to a sending station wave lengthapplicationof full volume across the speaker coil causesa series of loudvibrations and/or sqealing, etc.

The temperature actuated device may bepositioned within the cabinetof'the radioset at any point wherein the surrounding temperature isapproximately the same as that of the. roomv air. Alternatively, thedevice may be mounted external of the cabinet in say, a recess providedfor this purpose. T:

It will now be apparent my invention provides a novel combination of aradio receiver'adapted for normal use under normal conditions andserving the added function of an economical fire alarm.

Figure 4 illustrates my temperature actuated switch applied to a doorchime. The door chime comprises a chime bar 50, and a striker 5|actuated by the solenoid 52 that is energized by low voltage currentfurnished by the transformer 53 when the electrical circuit is completedby closure of the door-button switch 54. The temperature actuated switchcomprises the blades 55 and 56 carrying contacts 55a and 56arespectively said blades being spaced apart by the pellet 28 insertedbetween the blade 55 and a fixed surface 59, that may form the switchmounting plate. Alternatively the switch may take the form shown inFigure 1. The blade 55 is connected to one side of the transformer 53 bywire 51 while the blade 56 is connected by wires 63 to a fixed blade 58of a time delay relay T. The other elements of the time delay relaycomprise a bimetallic strip 66 having a heater winding 6| thereon, oneend of said winding being electrically connected directly to thebimetallic strip 60 and the other end of the winding being connected tothe solenoid 52 by the wire 62. Each of the blades 58 and 60 carries acontact 58a and 60a.

When the device is connected as shown in Figure 4 the door chime may beoperated in the normal manner, that is, every closure of the door switch54 causes the solenoid 52 to be energized thereby attracting the striker5| to strike the chime bar 50. In case of a fire in the vicinity of thepellet 28 the rapid increase in air temperature causes the pellet tomelt. When this occurs the blade 55 springs toward the blade 56 andcontacts 55a and 56a close. Closure of contacts 55a and 55a completes anelectrical circuit between solenoid 52 and the transformer 53 asfollows: wire 51, contact 55a, contact 56a, wire 63, contact 58a,contact 60a, winding 6|, wire 62, solenoid 52, and wire 64. This causesthe striker 5| to strike the chime bar 50. Although the contacts 55a and56a of the temperature actuated switch remain closed, the contacts 58aand 60a of the bimetallic relay T eventually open due to the heatgenerated by the current flowing through the heater winding 6|, as iswell known in the art. Upon opening of the contacts 58a and 6011 thecircuit to the solenoid 52 is broken permitting the striker 5| to dropback to its normal position and at the same time removal of current fiowthrough the heater winding 6| permits cooling of the bimetallic strip66. Upon cooling, the bimetallic strip 60 moves toward the fixed blade58 causing closure of the contacts 58a and 66a to thereby again completethe electrical circuit and cause a second sounding of the chime. Byproper design of the heater winding 6| and the solenoid 52 the'recycling period of the circuit can be made relative short therebycausing a rapid actuation of the chime to serve as a fire warning. It isapparent several temperature actuated switches of the type described canbe connected to a single door chime, each switch located in a section orroom of a structure to serve as a guardian instantly ready to sound analarm should fire break out in such location.

While I have described this particular embodiment of the invention withreference to a single stroke door chime itis apparent the sameconsiderations hold with respect to a conventional door bell or buzzer.Also, the invention is equally adapted for use with the various motordriven multiple chime devices.

Figure 5 illustrates an electrical alarm clock in combination with atemperature actuated control. In clocks of this type the alarm soundingmember usually comprises a fiat strip of softiron fastened or pivoted atone end and disposed adjacent to the field structure of the drivingmotor. Normally, the soft-iron strip is held somewhat away from themotor field structure by mechanical means associated with the settablealarm mechanism. At the pre-set time the alarm mechanism removes theobstruction in the path of the soft-iron strip whereby the strip ismagnetically attracted to the field structure of the motor. As clocks ofthis type operate on alternating current and as the soft-iron strip isfastened on one end, the strip vibrates rapidly against the motor fieldstructure producing a loud, buzzer-type noise.

A clock made in accordance with this embodiment of the invention isprovided with an auxiliary soft-iron strip 65 secured on one end by arivet 66 to the case 61. The strip 65 extends through an opening in thecase and lies adjacent to the field structure 68 of the driving motor.The temperature sensitive pellet 28 is inserted bteween the soft-ironstrip 65 and a bracket 69 secured to the exterior of the case 5?,substantially as shown. As long as the pellet 28 remains a solid thestrip 65 remains motionless. When the pellet 28 melts the strip 65 isattracted magnetically to the field structure and vibrates in the samemanner as the conventional electrical alarm.

It is is now apparent my invention provides a unique new combinationadapted to serve the normal, primary purpose of a pre-settable alarmclock and including simple yet positive means for sounding an alarmshould fire break out in the room in which the clock is located.

Having described the invention as related to an electrical alarm clockin which the temperature actuated alarm comprises an auxiliary alarmmember I do not intend that the invention be limited in this respect. Itis apparent the Figure construction is applicable to simple clocks thatdo not include a normal, pre-settable alarm. Also, the temperaturecontrol element is adapted for use with mechanical alarm clocks in whichcase the melting of the pellet 28 produces a mechanical motion to freethe clapper of such alarm clocks.

Having now illustrated and described several embodiments of myinvention, variations and modifications in the construction andarrangement of the parts will become apparent to those skilled in theart without departing from the spirit and scope of the invention as setforth in the appended claims.

Although the pellet type, temperature actuated switch is preferred otherwell known temperature sensitive devices such as a bimetallic switch,fusible wire switch, resistance device, etc., can be employed inpractising the broad aspects of the invention.

So far as I am aware it is broadly new to provide a combination devicecomprising a household sound producing member serving regularly aprimary purpose and including a temperature actuated device adapted toactuate said sound producing member when the temperature of thesurrounding air reaches a predetermined value.

I claim:

1. An electric clock of the type wherein an audible alarm is produced bya soft-iron member that vibrates against the field structure of the.motor when the motor is energized, characterized by the fact that thesoft-iron member is spaced from the said field structure in nonvibratingposition by a temperature sensitive member which changes from a solid toa fluid at a predetermined temperature above normal room temperature.

2. The invention as recited in claim 1, wherein the temperaturesensitive medium is disposed external with respect to the clock housing.

ANTHONY H. LAMB.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 471,929 Wooley Mar. 29, 18921,011,175 Egan Dec. 12, 1911 1,198,220 Hein Sept. 12, 1916 1,795,507Riccio Mar. 10, 1931 1,849,551 Praturlon Mar. 15, 1932 1,955,558 Nelsonet al Apr. 17, 1934 2,069,622 Perlman Feb. 2, 1937 2,147,718 Siddall etal. Feb. 21, 1939 2,318,005 McGuinness May 4, 1943 2,367,639 Conboy Jan.16, 1945 2,411,752 Padilla Nov. 26, 1946 2,417,254 Kelly Mar. 11, 1947

